The invention relates generally to earth moving devices in the form of a tractor drawn scraper bowl having improved means for dumping the soil when the scraper bowl is filled.
When operating under wet conditions, or in clayey soils, the soil collected in a scraper bowl is not easily dislodged. It has been a practice in the past to provide a rearwardly sliding floor section to uncover a front discharge opening and to provide an ejector plate to push the soil from the back of the bowl forwardly through the opening. Because of the pressing weight of the soil and the resistance of the soil to shearing action, large actuators must be employed for shifting a conventional movable floor section to create the opening and in subsequently shoving the soil along a fixed floor section for discharge through the opening. Indeed, the effect of the ejector plate is often to compact the soil into a tight mass which becomes firmly stuck to the floor of the bowl and to the bowl side sheets to produce a bracing reaction which may be sufficiently strong as to block the ejector plate against further forward movement. The scraper must be then shut down for cleaning, and it is sometimes necessary to suspend all scraping operations until the soil is more dry and friable. Such lost time is costly to the contractor.
It is, accordingly, an object of the present invention to provide a scraper bowl with a "rolling bottom", that is, a floor which may be simply "rolled" out of the way without shearing action to form a discharge opening, a floor which moves with the ejector plate, so that the soil is, in effect, transported on roller bearings from the back to the front of the bowl.
It is a more specific object of the invention to provide, in a scraper bowl, a floor in the form of a series of transversely extending strips which are articulated with respect to one another and which are supported upon an anti-friction roller train.
It is a general object to provide floor structure for both creating an opening at the front of the bowl and for transporting soil from the back of the bowl which is capable of operation using actuators requiring only a fraction of the power usually required for shifting a conventional floor section or shifting a conventional type of ejector plate, particularly under conditions when the soil is wet or clayey.
It is another object to provide an improved floor structure for a scraper bowl which enables increased promptness of discharge under both normal and difficult soil conditions permitting the scraper to make a greater number of round trips per unit of time, thereby bringing about a substantial improvement in scraping efficiency while decreasing the energy consumed per trip.
Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings.